Engine turbocharging systems



g; 20 25 25 CE 22 ENGINE TURBOGHARGING SYSTEMS Filed March 25, 1965 Carburetor 24 Turbocharger l7 Turbochurgerl7 Aftercooler-ZS INVENTOR SALVATORE S. SARRA BY d y L United States Patent- 3,232,042 ENGINE TURBOCHARGING SYSTEMS Salvatore S. Sarra, Miami, Fla., amignor to Daytona Marine Engine Corporation, Daytona Beach, Fla,

Filed Mar. 25,1963, Ser. No. 267,610 4 a 1 Claim. (Cl. 60-13) 1 This invention relates to new and useful improvements in internal combustion engines, and in particular the invention concerns itself with turbocharger-equipped engines wherein the fuel mixture upon leaving the carburetor is compressed prior to its admission to the engine cylinders.

The engine efficiency and performance benefits from turbo charging are, of course, well known, but these are inherently accompanied by a disadvantage which results from excessive heating of the fuel mixture and causes burnt valves, blown shafts, and other engine damage, as well as a loss of power when the fuel mixture temperature rises above approximately 110 F.

It is, therefore, the principal object of this invention to eliminate the above outlined disadvantage incident to turbocharging, this being attained by the provision of means for reducing the temperature of the fuel mixture after it has been turbocharged, so that it may be admitted to the engine cylinders at an optimum temperature for realizing the benefits of turbocharging without undue loss of power or engine damage due to excessive heat.

Although the invention is applicable to turbocharged engines in general, it is particularly intended for use in engines having two banks of cylinders fed by two turbochargers from a single carburetor, as for example in instances where automobile engines are adapted for marine use. In such an environment, the fuel mixture cooling means are in the form of a single aftercooler which, according to the invention, is operatively connected to both turbochargers and to both cylinder banks, so that the need for two separate aftercoolers is eliminated. Another feature of the invention resides in providing the aftercooler with a water cooled heat exchange unit, which is particularly suitable for a marine engine as such.

Other objects, features and advantages of the invention will become apparent from the following description taken in conjunction with the accompanying drawing, wherein like characters of reference are used to designate like parts and wherein:

The drawing shows a diagrammatic illustration of an engine turbocharging system, embodying the aftercooler of the invention.

Referring now to the accompanying drawing in detail, the reference numeral designates an internal combustion engine which, in the instance illustrated, is a V-type engine having two banks of cylinders 12, 12' with pistons 13, 13 operatively connected to a common crankshaft 14. The cylinders 12, 12' have the usual inlet valve ports 15 and outlet valve ports 16, as will be readily apparent.

A pair of turbochargers 17, 17 are provided for the respective cylinder banks 12, 12', each turbocharger including a turbine 18 and a compressor 19 coupled to a common shaft 20. Exhaust ducts 21, 21' extend from the outlet ports 16 of the respective cylinder banks 12, 12 to the turbines 18 of the respective turbochargers 17, 17 for actuating the latter, exhaust gases being discharged from the turbines through suitable putlets 22.

' Fuel mixture to the compressors 19 of bothturbo chargers 17, '17 is supplied through a feedduct 23 having a single carburetor 24 mounted centrally thereon. As used herein, the term single carburetor is applied to one individual carburetor regardless of the number of throats. or barrels 25 which it may have, and such term is intended to be broad enough to also cover two or moreiindividual carburetors mounted side by side on the feed duct 23, in the context that the feed duct constitutes a single source of fuel mixture supply for both turbo chargers 17, 17.

The essence of novelty of the invention resides in the provision of a single aitercooler 26 for reducing the temperature of the turbocharged fuel mixture prior to its admission into the cylinder banks 12, 12. The aftercooler 26 is in the form of a housing or casting forming a chamber 27 therein, with a pair of inlets 28, 28' and a pair of outlets 29, 29' communicating with the chamber. The outlets of the compressors 19 of the respective turbochargers 17, 17' are connected by ducts 30, 30 t0 the respective inlets 28, 28' of the aftcrcooler, while the aftercooler outlets 29, 29 are connected by ducts 31, 31' to the inlet ports 15 of the respective cylinder banks 12, 12'.

The aftercooler chamber 27 contains a heat exchange unit 32 which may conveniently be in the form of finned tubing, or the like, arranged to have cool water passing therethrough for reducing the temperature of the turbocharged fuel mixture which flows through the aftercooler, so that the fuel mixture is at an optimum temperature for admission to the engine cylinders. 'I his optimum temperature is approximately F. and the heat absorption effect of the exchanger 32 is such as to facilitate cooling of the fuel mixtureto approximately that temperature, from an approximate temperature of at which the fuel mixture leaves the turbochargers. The temperature reduction so obtained avoids losses in efficiency and performance due to excessive heat, lowers the fuel octane requirements to between 78 and 80, safeguard-s against detonation hazards, and avoids undue damage to engine parts.

It will be noted that the single attercooler 26 eliminates the need for two separate aftercooling units in conjunction with the two turbochargers and two cylinder banks and that the arrangement of the aftercooler cham- 'ber 27 with its pair of inlets 28, 28 and outlets 29, 29' also facilitates balancing of fuelmixture pressure as between the two turbochargers and the two cylinder banks, so that if for some reason the compressor of either turbocharger should be operating at a higher speed, pressure and/or fuel mixture temperature than the other, the temperature and pressure of the fuel mixture admitted to the two banks of cylinders will be the same.

While in the foregoing there has been described and shown the preferred embodiment of the invention, various modifications may become apparent to those skilled in the art to which the invention relates. Accordingly, it is not desired to limit the invention to this disclosure and various modifications and equivalents may be resorted to, falling within the spirit and scope of the invention as claimed.

What is claimed as new is:

In an internal combustion engine including two banks of cylinders, a pair of turbochargers one for each cylinder bank, each of said turbochargers including a compressor and a turbine, a pair of exhaust ducts extending from each cylinder of each of the respective cylinder banks to 3 the turbines of the resiiective turbochargers for driving the same, a single fuel mixture duct extending between and communicating with the compressors of said turbochargers, a canburetor provided centrally on said fuel mixture duct for delivering a fuel mixture therethrou-gh to the compressors ofboth turbochargers, a single aftercooler with water coo'led heat exchange means therein, a; pair of duct extending from the compressors of thercspeotive turbochargers to said single aftercooler, and

a further pair of ducts extending from the single after- 10 cooler to each cylinder of each of the respective cylinder banks.

" References Cited by the Examiner UNITED STATES PATENTS MARK NEWMAN, Primary Examiner.

JULIUS E. WEST, RICHARD B. WILKINSON,

Examiners. 

